/// whichParent:车辆类型或者车身颜色
/// whichChild:只用于车身颜色的第几个下拉框
typedef SelectItemChanged<T> = void Function(T value, String whichParent, String whichChild);
/// whichParent:车辆类型或者车身颜色
/// whichChild:只用于车身颜色的第几个下拉框
typedef TextChanged<T> = void Function(T value, String whichParent, String whichChild);

/// Signature for callbacks that report that a value has been set.
///
/// This is the same signature as [ValueChanged], but is used when the
/// callback is called even if the underlying value has not changed.
/// For example, service extensions use this callback because they
/// call the callback whenever the extension is called with a
/// value, regardless of whether the given value is new or not.
///
/// See also:
///
///  * [ValueGetter], the getter equivalent of this signature.
///  * [AsyncValueSetter], an asynchronous version of this signature.
typedef ValueSetter<T> = void Function(T value);
